Hydraulic fan drives



Nciv. 17, 1959 Original Filed June 26, 1948 C. F. BACHLE EI'AL HYDRAULIC FAN DRIVES 2 sheets-sheet 1 INVENTORS CARL E BAGHLE EDWARD A. HULBERT Nov, 17, 1959 j c. F. BACHEE ETAL. 2,913,083

HYDRAULIC FAN DRIVES Original Filed June 26, 1948 2 Sheets-Sheet 2 INVENTORfi CARL F BAOHLE Avenue-r5.

nited States HYDRAULIC FAN DRIVES Carl F. Bachle and Edward A. Hulbert, Grosse Pointe, Mich, assignors to Continental Motors Corporation, Detroit, Mich, a corporation of Virginia Continuation of abandoned application Serial No. 35,336, June 26, 1948. This application May 18, 1954, Serial No. 430,526

2 Claims. Cl. 192-61 It is therefore desirable to provide for such vehicles a fan drive which will yield instead of break down when it is overloaded for one reason or other.

It is an object of this invention to provide power transmitting mechanism which will transmit a predetermined torque for normal operating conditions, but which has sumcient flexibility to yield without failure of anyof.

the parts which the torque exceeds a predetermined maximum. This and other objects are accomplished in a drive which includes a fluid gear pump and a valve arranged to impede flow of fluid from the pump.

In the drawings:

Fig. 1 is a view in section through a power transmitting mechanism made according to the invention; more specifically, Fig. 1 is a view in sectionon line 11 of Fig. 2; and

Fig. 2 is a horizontal plan view with partsbroken away and in section of the power transmitting mechanism.

A fan or blower 2 is mounted for rotation in housing 4. 'A hollow shaft 6 is connected to be driven by the engine through any suitable means such as the gear train '7. Shaft 6 is rotatable in bearings 8 and 1-0, and is splined to a drive sleeve 12. Sleeve 12 is in turn connected to drive a suitable fluid pumping instrumentality,

such as a gear pump. The gear pump is connected to be driven through the sleeve by the shaft 6 which the shaft rotates relatively to the power utilizer, in this case the fan 2. In the embodiment shown, a gear pump is shown, but obviously other types of pumps may be employed, if so desired.

The gear pump, as here shown, comprises a sun gear 14 splined to the sleeve 12 to be driven thereby, and a plurality of planet gears 16 meshing with the sun gear 14 and mounted on the fan'2- by means of stub shafts 18 are carried by the spider 20, to which the fan blades are secured to the spider 20 by any suitable means, such as studs 24. A cover 26is secured to the housing by any satisfactory fastening means such as bolts 28.

A conventional suitable .oil seal 30 is provided between the spider 2t) and the bearing plate 32, and an antifriction thrust bearing 34 and other plain bearings 34a are provided to permit rotation of the shaft and sleeve assembly relatively to the pump housing 22. A sealing ring 36 is provided in a groove 38 beneath the sun gear, and a second sealing .ringr4tl is provided in groove 42 under each planet gear 16. Grooves 38 and 42 are supplied with fluid under pressure by means of the Y shaped passage 44 which communicates with the high pressure side of the gear pump as is best seen in Fig. 1,

atent and the sleeve.

" available for the intake side of the pump is replenished pump,fthe shaft 6 is hollow, as has been pointed ft above and. provides thus a passagefor additional'fltiid. Flu'id passes upward throughplug 64 into the interior of A fluid conduit 46 'is provided in the pump housing "22 and is arranged to receive'fluid under pressure from the gear pump, as is best seen in Fig. 2. A valve is disposed in conduit 46 in such a manner as to impede the passage of fluid through the conduit. More specifically, a valve body 48 is provided in the conduit. A plurality of circumferentially spaced holes 50 in the valve body communicate with an annular recess 52 in the pump housing 22 and provide passage for the oil from the annular recess '52 to the interior of the valve body.

A valve seat 54 in the valve body cooperates with the closure member 56 to restrict or close the fluid conduit 46 to the passage of high pressurefluid. When the closure 56 is in its open position, fluid may pass outward through holes 58 to annular recess 60, whence the fluid thus released passes into the space occupied by the gear pump housing and again becomes available to the suction side of the pump through passage 60a.

As is best seen in Fig. '2, the axis of movement of the closure member 56 is substantially radial, and the valve seat and closure are so arranged that radial outward arranged to be biased. toward valve closing position by centrifugal force derived from rotation of the fan 2 and housing 22. A spring 62 aids centrifugal force in biasing:

the closure toward the valve closed position pump space available to. the suction side of the. gear.

the shaft 6., and pass'esjthrough one or more holes 66in the shaft into the annularspace, ds-between the shaftannular space 68 and is provided with a ball check valve 72 through which fluid may pass outwardly to the space 26a asthrough passage 60a and thence to the gear pump.

Thus any loss of fluid from the chamber or. space 26a.

through valve 72.

In the event that the fan 2 is stalled forlong periods of time, fluid pressure in the space above the gear pump may build up to an excessive value. To prevent-this, a

1 ball check valve 74 isprovided in the end of shaft 6to relieve excessive pressure by communicating the .gear pump space to the interior of shaft 6 and to permit fluid.

to flow from that space into the hollow shaft.

For normal'operation, the torque requiredto drive the, fan 2 is not great enough to provide more than a nomi nalamount-of'slip, or relative rotation, between the fan and shaft 6, and the closure '56 of the valve is maintained 1 inthe closedornearly closed position by spring 62' and centrifugal force.

'If the fan is suddenly immersedin a much denser fluid, such as water, or if the torque suddenlyincreasesi for 'any reason, the fluid pressure generated becomes. enough to overcome theforce of spring 62and Celltlifllgaili force, and the closure 56 is unseated'to permit the pas-f sage of high pressurefluid through the conduit 46; If the fan 2,is, completely stalled, there is of. course no.

longer. any centrifugal force to bias the valve closure 56 intoits seated position, and under those circumstances,

the; only, force tending to move the valve closuretoward its seated p'ositionmwill be the force of spring 62. As. soon,,as, the excessive resistancetofan rotation has' been removed, spring 62.is enabled 'to move closure .56?

against the valve'seat, and the fan again begins to rotate.

The hollow shaft 6, the fluid passage 70 and the ball check valve 72 assure that there will always be fluid available to the suction side of the gear pump. The ball Patented Nov. 17., 1959 In order that there may always be fluid in the gear A passage '70 communicates withthe check valve 74 assures that no excessive pressure will be allowed to build up on the low pressure side of the gear pump.

The practical application of thepresent invention. is the mounting of this fan driving mechanism in a vehicle. The fan is driven from the engine crankshaft through a clutch mechanism as described above.

The vehicle, operating under normal conditions, drives the fan 2 because there is little resistance to the rotation of the driven element, the engine cooling fan. The vehicle now attempts to ford a stream, and the fan becomes immersed in water at least a sufficient amount to apply considerable resistance to fan rotation. The'fan slows down and there is at once a relative rotation, betweenthe driving and driven elements causing the gear pump to operate and apply fluid pressure'to the valve closure 56 to declutch the driving and driven elements. The fan can now stand still. But as soon as the vehicle leaves the stream and the fan is lifted out of the water, the spring 62 applies some initial movement to the valve closure 56 to close off the fluid outlet and thus the fan and. drive is again positively clutched together.

The declutching mechanism is actuated in response to a resistance applied directly to the driven element (the fan). More particularly, when the driving and driven elements are clutched together, the'fluid pump is inoperative. Centrifugal forces lock the gear 16 against relative rotation with respect to gear 14 and there is no pumping of fluid. Since gear 16 is carried by the driven element or fan, it is only by slowing down the fan that weobt'ain relative rotation of gears 14 and16, resulting in the pumping of fluid (oil in this case) and the pressure of this oil is utilized to effect a positive declutchin'g of the fan with the drive shaft. As long as there is suchresistance present to retard the rotation of the fan, the fluid pump or broadly the clutching meansjis actuated to declutch the fan and drive shat This application is a continuation of applicants copending application Serial No. 35,336, ,filed June-2 6, 1948, now abandoned.

We claim:

1. In a power transmitting mechanism, afldriven element, a driving element, and means associated with said driving and driven elements and having automatically operated clutching and de-clutching mechanism comprising a centrifugally actuated member carried by'tlie driven element and operable by the centrifugal force resulting from rotation of the driven element toelfect clutching of a driving and driven elements,,and spring means-initially loading said member to urge thesame radially outwardly in the same direction as urged by said centrifugal force, and means operable to overcome the force of said spring means upon the build-up of force resisting therotation of the driven element to therebyactuatethemem her to de-clutch said driving and drivenelements and to maintain said'elements in a 'de-clutched relation as long as such force resisting said rotation of thedriven element exists, said means operable when the forces resisting rotation of the driven element areremoved to'permit said spring means to again urge said member radially outwardly to begin such clutching of said elements and thereby effect full clutching of such elements by reason of the centrifugal forces on said member by reason of the rotation of said driven element, said mechanism comprising a gear pump having a sun gear connected to be driven by said driving element and a planet gear carried by said driven element, a fluid conduit connected to receive fluid under pressure from the gear pump when operable because of the relative rotation of the driven element with respect to said driving element, and said member comprising a valve in the conduit constructed and arranged to be biased towards its closed position by centrifugal force derived from rotation of the driven element, said spring means aforesaid acting on said valve, said valve when closed acting to impede fluid flow in said conduit and serving to lock said driven element to said driving element into direct driverelation, a second valve arranged to admit fluid to the system to replenish any losses of fluid, and a release valve associated with said system and communicating with the intake side of said gear pump to relieve excessive pressure built up in said system.

2. In a power transmitting mechanism for an internal combustion engine, a driven element, a driving element adapted to be driven by said engine, and a clutching means associated with said driving and driven elements, said clutching means comprising an actuated member carried solely by the driven element, said member being constructed and arranged to be actuated predominently by centrifugal force resulting from rotation of the driven element and to effect variable clutching of said driving and driven elements to a degree proportional to the aforesaid centrifugal force, spring means initially loading said member and resiliently urging same radially outwardly in the same direction as urged by centrifugal force to initiate the aforesaid clutching, and means operable to overcome the force of said spring means, and centrifugal force upon the build-up of force resisting rotation of said driven element and to actuate said member to positively effect de-clutching of said driving and driven elements and to maintain same in a de-clutched relation throughout the existence of the aforesaid resisting force to permit substantially unrestricted operation of said driving element, said last mentioned means operable only upon cessation of the aforesaid resisting force to permit said spring means to again urge said member radially outwardly to initiate clutching of said elements and rotation of said driven element, the increasing speed of rotation of said driven element operable to increase centrifugal force actuating said member to effect fully clutching of said driving and driven elements, said last mentioned means comprising a gear pump having a sun gear connected to be driven by said driving element and a planet gear carried by said driven element, a fluid conduit connected to receive fluid under pressure from the gear pump when operable because of relative rotation of said driven element with respect to said driving element upon build-up of the aforesaid rotation resisting force, said actuated member comprising a valve disposed in said conduit and constructed and arranged to be biased toward a closed position predominently by centrifugal force derived from rotation of said driven element, said valve when so closed being operable to impede fluid flow through said conduit and to restrict pumping operation of said gears to lock said driven element to said driving element in direct driving relation, the aforesaid spring means acting on said valve.

References Cited in the file of this patent UNITED STATES PATENTS 1,396,151 Wheeler Nov. 8, 1921 1,688,852 Christie Oct. 23, 1928 2,157,574 Siesel May 9, 1939 2,174,344 Sinderson Sept. 26, 1939 2,262,626 Thorne Nov. 11, 1941 2,311,237 Loveday Feb. 16, 1943 2,371,227 Dodge Mar. 13, 1945 2,377,350 Marsh June 5, 1945 2,418,625 Cornelius Apr. 8, 1947 2,484,015 Cochran Oct. 11, 1949 2,526,175 Van Alstyne et al. Oct. 17, 1950 FOREIGN PATENTS 76,193 Sweden Oct. 27, 1930 

